The fundamental advantage of Porifera’s membrane technology is based on the large enhancements of the fluid and gas flow in carbon nanotube pores. This enhancement, first reported on the cover of Science magazine in 2006, was discovered at the Lawrence Livermore National Laboratory by a group of scientists led by Porifera’s principal R&D team. Porifera has secured the exclusive license to the intellectual property resulting from that discovery.
Carbon nanotubes are seamless, atomically smooth carbon “straws” whose diameters range from less than a nanometer to tens of nanometers (a water molecule is ~0.3nm). Water flows through these unique pores 1,000 times faster than through any other pore of similar diameter. Moreover, gases also flow through the nanotubes pores more than 100 times faster than through any other nanometer scale pore. This reduction in flow resistance manifests itself in large enhancements of the membrane permeability and in drastic reduction of viscous losses. Computational studies demonstrate that the high permeability is inherent to the carbon nanotube pores due to their unique combination of their atomic smoothness and hydrophobicity and that it could not be replicated with pores made by any other material. Nanotube membranes also exclude ions while keeping the inherent advantages in the flow rates.
Porifera membranes promise vastly superior performance at similar cost relative to current membranes used in liquid phase separations. These membranes provide superior permeability, selectivity, and durability, which translate into substantially lower costs for the system, filter elements, and energy required to operate.
Porifera’s carbon nanotube membrane offers another distinct advantage over the existing classes of polymeric membranes: it’s a simple straight pore system whose performance can be custom-tailored using rational design. In Porifera membranes, the three important membrane characteristics-pore size, pore entrance and exit characteristics, and membrane matrix - can be modified independently. Such capability offers a robust approach to designing and manufacturing membranes that are built on a single platform, but are still custom-tailored for improved performance in a specific application.
Further Reading
Fast transport in carbon nanotubes described in layman’s terms
Review on Science and technology for water purification in the coming decades
Perspective on Carbon Nanotube Membranes
Research article reporting the discovery of fast transport in sub 2nm carbon nanotubes
Review on CNT membranes in Nano Today
First demonstration of ion rejection by carbon nanotube pores
Bruce Hinds’ group at the University of Kentucky
Eva Marand’s Research group at Virginia Tech